diff --git a/misc/fuel/fuel-edit.el b/misc/fuel/fuel-edit.el
index 20e1f1eb01..b0756826f1 100644
--- a/misc/fuel/fuel-edit.el
+++ b/misc/fuel/fuel-edit.el
@@ -33,6 +33,11 @@
 
 ;;; Auxiliar functions:
 
+(defun fuel-edit--looking-at-vocab ()
+  (save-excursion
+    (fuel-syntax--beginning-of-defun)
+    (looking-at "USING:\\|USE:")))
+
 (defun fuel-edit--try-edit (ret)
   (let* ((err (fuel-eval--retort-error ret))
          (loc (fuel-eval--retort-result ret)))
@@ -92,9 +97,9 @@ With prefix, asks for the word to edit."
                    (fuel-completion--read-word "Edit word: ")))
          (cmd `(:fuel* ((:quote ,word) fuel-get-edit-location)))
          (marker (and (not arg) (point-marker))))
-    (condition-case nil
-        (fuel-edit--try-edit (fuel-eval--send/wait cmd))
-      (error (fuel-edit-vocabulary nil word)))
+    (if (and (not arg) (fuel-edit--looking-at-vocab))
+        (fuel-edit-vocabulary nil word)
+      (fuel-edit--try-edit (fuel-eval--send/wait cmd)))
     (when marker (ring-insert find-tag-marker-ring marker))))
 
 (defun fuel-edit-word-doc-at-point (&optional arg word)
diff --git a/misc/fuel/fuel-font-lock.el b/misc/fuel/fuel-font-lock.el
index 10561ded68..4b5520b8f9 100644
--- a/misc/fuel/fuel-font-lock.el
+++ b/misc/fuel/fuel-font-lock.el
@@ -88,6 +88,16 @@
   `((,fuel-syntax--stack-effect-regex . 'factor-font-lock-stack-effect)
     (,fuel-syntax--brace-words-regex 1 'factor-font-lock-parsing-word)
     (,fuel-syntax--vocab-ref-regexp  2 'factor-font-lock-vocabulary-name)
+    (,fuel-syntax--constructor-regex (1 'factor-font-lock-word)
+                                     (2 'factor-font-lock-type-name)
+                                     (3 'factor-font-lock-invalid-syntax nil t))
+    (,fuel-syntax--typedef-regex (1 'factor-font-lock-type-name)
+                                 (2 'factor-font-lock-type-name)
+                                 (3 'factor-font-lock-invalid-syntax nil t))
+    (,fuel-syntax--rename-regex (1 'factor-font-lock-word)
+                                (2 'factor-font-lock-vocabulary-name)
+                                (3 'factor-font-lock-word)
+                                (4 'factor-font-lock-invalid-syntax nil t))
     (,fuel-syntax--declaration-words-regex . 'factor-font-lock-declaration)
     (,fuel-syntax--word-definition-regex 2 'factor-font-lock-word)
     (,fuel-syntax--alias-definition-regex (1 'factor-font-lock-word)
diff --git a/misc/fuel/fuel-syntax.el b/misc/fuel/fuel-syntax.el
index 4112e3507d..ca247cf8f0 100644
--- a/misc/fuel/fuel-syntax.el
+++ b/misc/fuel/fuel-syntax.el
@@ -187,6 +187,7 @@
                 "QUALIFIED-WITH:" "QUALIFIED:"
                 "RENAME:"
                 "SINGLETON:" "SLOT:" "SYMBOL:"
+                "TYPEDEF:"
                 "USE:"
                 "VAR:")))
 
@@ -208,6 +209,15 @@
           (format ":[^ ]* [^ ]+\\(%s\\)*" fuel-syntax--stack-effect-regex)
           "M[^:]*: [^ ]+ [^ ]+"))
 
+(defconst fuel-syntax--constructor-regex
+  "\\_<C: +\\(\\w+\\) +\\(\\w+\\)\\( .*\\)?$")
+
+(defconst fuel-syntax--typedef-regex
+  "\\_<TYPEDEF: +\\(\\w+\\) +\\(\\w+\\)\\( .*\\)?$")
+
+(defconst fuel-syntax--rename-regex
+  "\\_<RENAME: +\\(\\w+\\) +\\(\\w+\\) +=> +\\(\\w+\\)\\( .*\\)?$")
+
 
 ;;; Factor syntax table